Interspecific variability of class II hydrophobin GEO1 in the genus Geosmithia
Language English Country Netherlands Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
25442290
DOI
10.1016/j.funbio.2014.07.005
PII: S1878-6146(14)00118-4
Knihovny.cz E-resources
- Keywords
- Ascomycetes, Genetic diversity, Hypocreales, Intragenic tandem repeats, Protein evolution,
- MeSH
- Ascomycota genetics isolation & purification MeSH
- DNA, Fungal chemistry genetics MeSH
- Exons MeSH
- Fungal Proteins genetics MeSH
- Phylogeny MeSH
- Genetic Variation * MeSH
- Introns MeSH
- Membrane Proteins genetics MeSH
- DNA, Ribosomal Spacer chemistry genetics MeSH
- Molecular Sequence Data MeSH
- Amino Acid Sequence MeSH
- Sequence Analysis, DNA MeSH
- Sequence Homology, Amino Acid MeSH
- Cluster Analysis MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA, Fungal MeSH
- Fungal Proteins MeSH
- Membrane Proteins MeSH
- DNA, Ribosomal Spacer MeSH
The genus Geosmithia Pitt (Ascomycota: Hypocreales) comprises cosmopolite fungi living in the galleries built by phloeophagous insects. Following the characterization in Geosmithia species 5 of the class II hydrophobin GEO1 and of the corresponding gene, the presence of the geo1 gene was investigated in 26 strains derived from different host plants and geographic locations and representing the whole phylogenetic diversity of the genus. The geo1 gene was detected in all the species tested where it maintained the general organization shown in Geosmithia species 5, comprising three exons and two introns. Size variations were found in both introns and in the first exon, the latter being due to the presence of an intragenic tandem repeat sequence corresponding to a stretch of glycine residues in the deduced proteins. At the amino acid level the deduced proteins had 44.6 % identity and no major differences in the biochemical parameters (pI, GRAVY index, hydropathy plots) were found. GEO1 release in the fungal culture medium was also assessed by turbidimetric assay and SDS-PAGE, and showed high variability between species. The phylogeny based on the geo1 sequences did not correspond to that generated from a neutral marker (ITS rDNA), suggesting that sequence similarities could be influenced by other factors than phylogenetic relatedness, such as the intimacy of the symbiosis with insect vectors. The hypothesis of a strong selection pressure on the geo1 gene was sustained by the low values (<1) of non synonymous to synonymous nucleotide substitutions ratios (Ka/Ks), which suggest that purifying selection might act on this gene. These results are compatible with either a birth-and-death evolution scenario or horizontal transfer of the gene between Geosmithia species.
References provided by Crossref.org
GENBANK
HG792076, HG792077, HG792078, HG792079, HG792080, HG792081, HG792082, HG792083, HG792084, HG792085, HG792086, HG792087, HG792088, HG792089, HG792090, HG792091, HG792092, HG792093, HG792094, HG792095, HG792096, HG792097, HG792098, HG792099, HG792100, HG792101
